How high /tall for the ramp of the coop for the Bantam Cochins ?

[12eggs]

The coop would be 21 inches off the ground , so ramp going in , is not that high i guess. But my question ? is this too high for Bamtam Cochins ? Thank you MH

 

[ChickenCanoe]

They could probably fly or hop in there but if you glue or nail cleats onto the ramp they should be able to walk up.